1. Field of the Invention:
This invention relates to a wide band video signal recording apparatus and more particularly to an apparatus which is arranged to record a video signal of a wide frequency band in a multi-channelled state.
2. Description of the Related Art:
Varied specifications for high resolution wide band television signals have been proposed during recent years for the purpose of enhancing the quality of reproduced television (TV) signals. These proposed TV signals include, for example, the so-called high definition (hereinafter referred to as HD for short) TV signal which has 1125 scanning lines and a luminance signal band of 20 MHz or thereabout; the so-called extended definition (hereinafter referred to as ED for short) TV signal which has interchangeability with the present TV signal and has a luminance signal band of 8 MHz or thereabout.
For recording and reproduction of such wide band TV signals, the video tape recorders (VTRs) which are currently in use are not usable because of their limited recordable and reproducible frequency band of only 4 MHz or thereabout. To solve this problem, there have been proposed various VTRs which are arranged to record and reproduce the wide band TV in a multi-channel state with the frequency band of each channel limited to 4 MHz or thereabout. A technique of this kind has been disclosed in U.S. patent application Ser. No. 034,212 filed Apr. 3, 1987 which corresponds to Japanese Patent Application No. SHO 61-82932 and is assigned to the assignee of the present invention. However, with a VTR arranged to perform such multi-channel recording, the adverse effects of jitter, etc. must be accurately removed although a composite video signal can be divided and arranged into a multi-channel state by a simple method of dividing it into bands. To meet this requirement, the circuits of the reproduction system of the VTR must be arranged on a large scale. In case that the video signal is to be divided into a high frequency component and a low frequency component in particular, the time constants of circuits for handling these two components differ from each other. In that case, therefore, it has been extremely difficult to restore them back into the original state of video signal by matching them timewise.
Further, in cases where a composite video signal is arranged to be recorded by separating them into R, G and B components, each of them must be processed into a multi-channel state, because each of them is a wide band signal. In such a case, therefore, it is hardly possible to accomplish high density recording because of a great increase in the number of channels.
Further, it is desirous to have a VTR arranged to be capable of recording an audio signal, or a stereo-audio signal, if possible, at a high relative speed. However, the above stated method has hardly enabled VTRs to perform such audio signal recording.
To solve that problem, varied methods of digitally recording video and audio signals have been proposed. However, these methods result in a further broadened band, which forbids high density recording.